This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Heparin and heparin-like molecules are known to modulate the responses of endothelial cells to vascular endothelial growth factor-A (VEGF-A). In this collaboration, we have been investigating the likely mechanisms for heparin/heparan sulfate's influence on the biological activity of VEGF-A using heparan sulfate deficient mouse endothelial cell lines derived from heparan sulfate mutant mice.